Machine clamp



Jan. 4, 1966 SEQUIN 3,227,438

MACHINE CLAMP Original Filed June 7, 1955 United States Patent 3,227,438MACHINE CLAMP Hector Sequin, 488 S. Alkire St., Denver, Colo.Continuation of application Ser. No. 513,673, June 7, 1955, andapplication Ser. No. 71,202, Nov. 23, 1960. This application Aug. 27,1964, Ser. No. 394,376

3 Claims. (Cl. 269-94) The present application is a continuation of mycopeudiug application Serial Number 71,202, filed November 23, 1960 andSerial Number 513,673, filed June 7, 1955 and now abandoned, and relatesto new and useful improvements in machine clamps and more particularlyto a counterweighted hold down clamp. The clamp of the present inventionis used for securely clamping an irregular shaped work piece in apre-selected location on a machine bed.

Various devices have been used for this purpose throughout the years,however, none have been so practical as to replace the ordinary flatclamp. The flat clamp is used with a step block and shims, with the stepblock being built up to an equivalent height of the workpiece, whichpermits the clamp to be secured in a position parallel to the machinebed. Since this necessitates trial and error to establish a secureclamp, costs mount, while the production of parts is very slow.

It is therefore a primary object of the present invention to provide anew and unique one piece machine clamp which can be quickly positionedwithout the use of shims, which will adequately position a workpiece ona machine bed.

Another object of the invention is the provision of a machine clampwhich is counterweighted for ease of operation and can be used on a widevariety of parts ranging from very thin to thick.

Still another object of the invention is the provision of a one-piecemachine clamp which is inexpensive, while being durable and capable ofbeing manufactured by modern mass production methods.

It is a further object of the invention to provide a machine clamp whichis so constructed and arranged so that the work engaging surface willnot damage the work surface, nor will the counterweighted portionthereof damage the machine bed, when the clamp is secured to aworkpiece.

The above and other objects of the present invention can be accomplishedby the provision of a counterweighted hold down clamp having two workholding fingers arranged in generally parallel relationship on one endthereof and a broad, heavy flat bottomed heel portion which forms acounter weight and engages the bed of the machine on which the clamp isused; said broad heavy heel having an arcuate pivotal section at theforward tangential edge of said heel portion; said parallel work holdingfingers separated by a continuous open end slot which terminates forwardof said heel portion and generally perpendicular to the flat bottomsurface thereon; the top surfaces of each of said fingers being formedon a smooth sweeping arc, while a second arc is located intermediate thearcuate pivotal section and the flat work engaging surfaces on the workholding fingers; the flat surfaces thereof extend in generally parallelrelationship to said fiat bottom heel portion, while the forward edgesof said work holding fingers are provided with an arcuate portionintermediate the respective surfaces, thereby reducing the possibilityof damage to the workpiece on which the clamp is used; the broad, heavy,counterweighted heel portion on the underside of said work holdingfinger-s extends approximately one third of of the overall length of theclamp; said clamp secured in position with a nut and bolt, said nutengaging a pad 3,227,438 Patented Jan. 4, 1966 ice having an arcuateportion thereon which is engaged with the upper arcuate surface of thework engaging fingers, while the bolt is disposed between the Workholding fingers and the machine bed; engagement of one of said fingerswith said workpiece through rotation of said nut clamping said workpiecesecurely in position.

Other objects of the invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingswhich form a part of this specification, wherein like referencecharacters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a fragmentary perspective view of a machine bed and aworkpiece held in position thereon by the machine clamp of the presentinvention.

FIGURE 2 is a plan view of the machine clamp shown in FIGURE 1.

FIGURE 3 is an elevational view of the machine clamp and nut shown inFIGURE 1.

FIGURE 4 is a sectional view of the clamp taken along lines 44 of FIGURE3.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in thedrawings, since the invention is capable of other embodiments and ofbeing practiced or carried out in various ways. Also, it is to beunderstood that the phraseology or terminology employed herein is forthe purpose of description and not of limitation.

FIGURE 1 of the drawings illustrates a generally fiat machine bed 10,having T-slots 12 and 14 longitudinally disposed therein. Said slotsbeing adapted to accommodate the head of a bolt. A workpiece 16 issecured to the machine bed with the clamp 18 which embodies the presentinvention.

The general configuration of the machine clamp 18 is shown in FIGURES1-3. The machine clamp of the present invention has a wide, heavy,counterweighted heel portion 20 and a pair of parallel work holdingfingers 22 and 24 which extend outwardly therefrom. The upper surface ofthe heel portion and the upper surface of the work holding fingers 22and 24 tangentially blend into a smooth, uninterrupted curve asindicated at 26. The bottom surface 28 of the heavy counterweighted heelis generally fiat, while the forward edge thereof is provided with aportion 30 which tangentially intersects the underside of the clamp. Theunderside of the fingers 22 and 24 are curved and tangentially blendwith the cylindrical portion 30 to provide a smooth uninterrupted arc.

Flat work engaging tips 32 and 34 are provided at the ends of each ofthe fingers 22 and 24 to hold a workpiece 16. A threaded nut 39 isprovided for positioning and securing the clamp to a workpiece. A pad 36is disposed beneath said nut 39. Said pad 36 has a concave underside ofsubstantially the same configuration as the top of each of the fingers,while the top of the pad is generally fiat. Thus, when the clamp ispivoted about the cylindrical portion 30 of the counterweighted base 20,the threaded nut 39 can be operatively positioned in substantiallyperpendicular relationship to the bolt 38, to clamp the workpiece inposition.

As illustrated in FIGURE 1, the bolt 38 is disposed between the parallelfingers 22 and 24 in the slot 40, the head end being in the T-slot,while the threaded end is through the pad 36 and has the threaded nut 39positioned thereabout.

In use, the broad heavy, counterweighted heel 28 of the machine clamp isplaced in contact with the generally fiat bed of the machine 10. Thecounterweighted heel portion maintaining the parallel relationship ofthe underside of the work holding fingers 22 and 24, with the machinebed 10. Therefore, when the clamp is positioned on the bed of themachine, and the nut 39 turned down securely, the workpiece isefficiently clamped in position. Since the tips 42 and 44 are rounded,no damage will result when contact is made with the workpiece, nor willany damage occur on the bed of the machine as a result of the contact ofthe portion 30. The clamp of the present invention will accommodate allclamping requirements, since the gripping surfaces provided are indirect proportion to the thickness of the workpiece 16.

From the foregoing description, it will be apparent that the presentinvention is superior to any clamps either present or past, that theclamp of the present invention can be used to clamp any thicknessworkpiece without the use of shims or step blocks and the clamp of thepresent invention when used is not only durable, but will minimize thetime of application which will ultimtaely reduce the price of the endproduct manufactured.

Having thus described my invention, I claim:

1. In a machine clamp, the combination of, a broad counterweighted heelportion having a generally fiat bottom with front and rear edgesthereon;

a pair of work holding fingers extending from said counterweighted heelportion;

said work holding fingers located in substantially parallel relationshipand having a slot therebetween; said slot terminating at the heelportion in perpendicular relationship to the flat bottom portionthereof;

said work holding fingers having a curved upper and a curved lowersurface thereon which surfaces intersect in tangential relationship thecurved portions on the front and rear edges of the broad counterweightedheel;

the upper surface of said work holding fingers have positioned thereon apad having a curved underside cooperable with the upper surface of saidwork holding fingers, the top of said pad being flat to cooperate withthe under surface of a threaded nut secured to a bolt positioned betweensaid work holding fingers and secured to a machine base.

2. In a counterweighted work holding clamp, the combination of,

a broad counterweighted, flat bottomed heel portion having two workholding fingers which extend therefrom;

said broad, counterweighted heel portion having an arcuate pivotalsection at the forward tangential edge thereof;

said work holding fingers having a continuous open end slot whichterminates forward of said heel portion and in generally perpendicularrelationship to the flat bottom surface thereof;

a top and bottom surface on said work holding fingers;

the top surface of each of said work holding fingers is arcuate;

the bottom surface of said work holding fingers tangentially intersectsthe arcuate pivotal section on the heel portion and the forward edge ofthe work holding fingers;

the forward edges of the work holding fingers are provided with anarcuate portion intermediate the respective curved surfaces thereof,thereby reducing the possibility of damage to the workpiece on which theclamp is used.

3. A clamp as in claim 2, wherein said broad counterweighted heelportion extends approximately one third of the overall length of theclamp.

References Cited by the Examiner UNITED STATES PATENTS 1,801,222 4/1931Cayo 26993 2,365,079 12/1944 Huber 26993X FOREIGN PATENTS 107,926 7/1917GreatBritain.

WILLIAM W. DYER, J R., Primary Examiner.

ROBERT C. RIORDON, Examiner.

1. IN A MACHINE CLAMP, THE COMBINATION OF, A BROAD COUNTERWEIGHTED HEELPORTION HAVING A GENERALLY FLAT BOTTOM WITH FRONT AND REAR EDGESTHEREON; A PAIR OF WORK HOLDING FINGERS EXTENDING FROM SAIDCOUNTERWEIGHTED HEEL PORTION; SAID WORK HOLDING FINGERS LOCATED INSUBSTANTIALLY PARALLEL RELATIONSHIP AND HAVING A SLOT THEREBETWEEN; SAIDSLOT TERMINATING AT THE HEEL PORTION IN PERPENDICULAR RELATIONSHIP TOTHE FLAT BOTTOM PORTION THEREOF; SAID WORK HOLDING FINGERS HAVING ACURVED UPPER AND A CURVED LOWER SURFACE THEREON WHICH SURFACES INTERSECTIN TANGENTIAL RELATIONSHIP THE CURVED PORTIONS ON THE FRONT AND REAREDGES OF THE BROAD COUNTERWEIGHTED HEEL; THE UPPER SURFACE OF SAID WORKHOLDING FINGERS HAVE POSITIONED THEREON A PAD HAVING A CURVED UNDERSIDECOOPERABLE WITH THE UPPER SURFACE OF SAID WORK HOLDING FINGERS, THE TOPOF SAID PAD BEING FLAT TO COOPERATE WITH THE UNDER SURFACE OF A THREADEDNUT SECURED TO A BOLT POSITIONED BETWEEN SAID WORK HOLDING FINGERS ANDSECURED TO A MACHINE BASE.